Our collaborators in the Jaffrey laboratory at Cornell had previously reported the development of a fluorescent RNA module called 'Spinach' but further improvement was hampered by a complete lack of knowledge of its structural and biophysical basis of function. In 2014, we determined the structure of Spinach, revealing an unprecedented mode of RNA-fluorophore interaction, which relies on a G-quadruplex motif. To further the application of this kind of fluorogenic RNA in vivo, we have started to analyze the mechanism of action of G-quadruplex-specific helicase proteins.